1. Field of the Disclosure
The disclosure relates to a stacked-chip structure. Particularly, the disclosure relates to a testing and repairing apparatus of through silicon via in stacked-chip.
2. Description of Related Art
In recent years, the number of transistors in an integrated circuit (IC) is continuously increased, so that an IC usage area is accordingly increased. Regarding an overall operating time, increase of the IC area may aggravate problems of time delay and power consumption. In order to effectively mitigate the problems of time delay and power consumption, a three dimensional (3D) IC stacking technique is developed. In a 3D IC structure, multiple ICs are vertically stacked in a 3D space to achieve an optimal effect of reducing a structure size. Signals and a power voltage are transmitted between different ICs through a through silicon via (TSV) structure. Therefore, a connection length of different transistors and a delay time thereof are obviously shortened compared to a conventional planar circuit (2D), and meanwhile chip performance is improved and the power consumption is reduced.
A fabrication process of the 3D IC includes three parts: 1. formation of the TSV channel and filling of a conductive metal; 2. a wafer thinning process; and 3. chip stacking and combination. However, an insulation thin film (for example, SiO2) used as a sidewall of the TSV is probably broken or invaded by external impurity during the fabrication process, which may easily cause an open circuit of the TSV or a situation that the TSV is shorted to the ground. Alternatively, after the TSV is fabricated, when multiple ICs are stacked, a tiny position offset may cause the open circuit of the TSV or the situation that the TSV is shorted to the ground. The open circuit of the TSV represents that the TSV cannot provide an effective path between different ICs to transmit signals. The situation that the TSV is shorted to the ground represents that the TSV is unexpectedly connected to the ground. Anyhow, the grounded TSV cannot transmit signals.